Smart patches, such as electronic skin (e-skin), are pixelated flexible sensing array, which senses external and environmental stimuli, in a manner similar to human skin. Smart patches has been produced from diverse technologies, such as semiconducting organics, nanowires, carbon nanotubes, and nanofibres.
Although promising results have been achieved with these technologies, the multi-pixel integration, complicated wiring, applied voltage, and analysis remain challenges to overcome. For example, 10×10 pixelated smart patch requires 200-300 wiring devices and 100 electrical measurement devices, thus increasing the energy consumption and the smart patch cost.
In general, the electrical resistance of GNP film depends on the inter-particle distance. When a GNP film is deposited on a flexible substrate, deformation of the substrate affects the inter-particle distance in the film and the resistance changes accordingly.
A schematic representation of GNPs on an elastically deformed flexible substrate is depicted in FIG. 1A. However, for smart patches applications, many pixels and associated wiring are required. In a pixelated array of strain/pressure sensors, the resolution is limited by the pixel size, and sensitivity differences between pixels might reduce the overall pressure resolution and detection limit.